Jolin  Swett 


FIRST    LESSON 


NATURAL   HISTORY. 


BY 

MRS.    AGASSIZ. 


SECOND    EDITION. 


BOSTON: 
LITTLE,    BROWN   AND    COMPANY. 

LONDON: 
SAMPSON  LOW,  SON  AND   COMPANY. 

M  DCCC  LIX. 


oH 


Entered  according  to  Act  of  Congress,  in  the  year  1859,  by 

LITTLE,  BROWN  AND  COMPANY, 
In  the  Clerk's  Office  of  the  District  Court  of  the  District  of  Massachusetts 

c-uUCATION  DSP*. 


RIVERSIDE,   CAMBRIDGE: 
PRINTED  BY  H.  0.  HOUGHTON  AND  COMPAXIT. 


PREFACE. 


THIS  little  book,  which  it  is  hoped  may 
be  interesting  for  children,  and  perhaps  of 
some  use  to  parents  whose  children  share 
the  general  juvenile  delight  in  Aquariums, 
has  been  prepared  under  the  direction  of 
Professor  Agassiz,  and  owes  any  little  merit 
it  may  possess  to  his  advice  and  assistance. 


541764 


CONTENTS, 


SEA-ANEMONES   AND   CORALS 7 

CORAL   REEFS        •      • 28 

HYDROIDS    AND   JELLY-FISHES 43 

STAR-FISHES    AND    SEA-URCHINS 62 


FIRST    LESSON    IN    NATURAL    HISTORY. 


CHAPTER   I. 

SEA-ANEMONES  AND  CORALS. 

MY  DEAR  LiSA  AND  CONNIE, 

I  was  thinking  the  other  day  of  the  pleas- 
ant times  we  passed  together  at  the  sea-shore 
last  summer,  and  remembering  how  often,  in 
the  evening,  when  your  playtime  was  over,  and 
we  were  sitting  in  the  quiet  twilight,  waiting 
for  your  bedtime,  you  used  to  beg  for  stories ; 
and  it  occurred  to  me  that,  in  the  long  and 
snowy  winter,  I  might  prepare  some  stories  for 
next  summer,  and  then,  when  you  come  after 
tea,  and  say,  "  Now,  Aunt  Lizzie,  tell  us  a 
story,"  I  shall  have  one  all  ready,  and  I  need 
not  answer,  as  I  often  used  to  do,  that  my 
brain  was  empty,  and,  hunt  as  I  would,  I 


8  SEA-ANEMONES  AND  CORALS. 

coulvl  TKvt:  find  a  story  in  any  corner  of  it. 
But  vh&re :  is'.ohe  thing  you  may  not  like  about 
the  stories  I  think  of  writing  for  you;  I  want 
them  to  be  true  stories,  and  not  about  little 
boys  and  girls,  but  about  animals.  Do  you 
recollect  the  nets  I  made  for  you  last  sum- 
mer, and  how  you  used  to  catch  in  them  the 
tiny  little  fishes  that  lived  in  the  pool  left  by 
the  sea-waves  in  the  hollow  of  that  large  rock 
near  our  house?  Now,  thete  are  many  other 
animals  living  in  the  little  pools  left  by  the 
tide  on  the  beaches  and  between  the  rocks 
and  stones,  which  are  both  beautiful  and  cu- 
rious, and  which,  if  you  knew  a  little  more 
about  them,  would  interest  you  quite  as 
much  as  the  little  fishes  you  liked  to  see 
swimming  about  in  your  Aquarium  last  sum- 
mer. 

Have  you  ever  heard  of  a  Sea- Anemone  ? 
Don't  fancy,  from  its  name,  that  it  looks  any- 
thing like  the  pretty  white  or  pink  Anemones 
that  delight  you  so  much  in  the  woods  in 
spring,  and  yet  they  have  been  called  so,  be- 
cause, though  they  are  as  much  animals  as 
Berty's  little  dog  Pinky,  or  your  pussy-cat,  they 


SEA-ANEMONES  AND  CORALS.  9 

yet  have  a  look  like  a  flower.  But  this  is 
only  when  it  pleases  them  to  spread  out  their 
little  bodies,  and  flaunt  all  their  pretty  fringes; 
and,  as  you  will  see,  when  I  tell  you  a  little 
more  about  it,  they  can  shut  themselves  up, 
and  look  as  ugly  and  dull  as  they  please.  In 
this  you  see,  they  differ  very  much  from  a 
flower,  which  cannot  fold  up  its  leaves  and 
put  them  away  when  it  likes.  It  is  true  that 
some  flowers  close  at  night,  and  open  in  the 
day,  but  it  is  not  because  they  want  to  do  so, 
but  because  the  state  of  the  atmosphere  causes 
them  to  shut  and  open. 

Some  day  next  summer  at  Nahant,  we  will 
go  at  low  tide  in  search  of  a  Sea- Anemone, 
and,  if  we  are  fortunate,  we  shall  find  some- 
where among  the  rocks  near  Sunken  Ledge, 
one  of  these  ocean  flowers.  It  will  be  rather 
slippery  on  the  wet  sea-weed,  but  we  shall  not 
mind  one  or  two  tumbles,  if  we  find  what  we 
are  looking  for.  I  dare  say  we  shall  meet  with 
one,  hiding  himself  away  in  some  little  dark 
corner  of  the  rocks,  (for  they  rather  like  the 
shade,)  with  his  fringes  all  drawn  in,  appear- 
ing like  a  brown  soft  lump,  and  thinking  that, 


10  SEA-ANEMONES  AND  CORALS. 

because  he  has  made 
himself  look  so  ugly 
and  unattractive,  no- 
body will  disturb  him. 
*  Here  we  have  a 
No.  i.  drawing  of  him.  But 

we  will  not  be  deceived  by  his  uninviting 
looks.  "We  will  take  him  up  very  softly,  part- 
ing him  gently  with  our  fingers  from  the  rock, 
for  he  is  very  tender,  and  adheres  closely 
to  his  resting-place,  and  when  we  have  him 
safely  at  the  house  we  will  put  him  in  a 
glass  bowl  with  some  sea-weed  and  a  few 
stones,  that  he  may,  if  possible,  believe  him- 
self to  be  still  at  home  in  his  puddle.  And 
now  we  must  watch  him  long  and  patiently, 
if  we  would  see  how  he  changes  himself  into 
his  flower-like  form.  As  he  lies  now,  he  is 
like  nothing  but  a  ball  of  rather  dark,  soft 
substance,  flat  on  the  side  by  which  he  was 
attached  to  the  rock.  But  watch  him,  —  slowly, 
very  slowly,  for  he  has 'not  the  power  of  any 
quick  motion,  —  he  begins  to  expand,  —  the  little 

*  This  and  the  three  following  wood-cuts  represent  the  common 
Sea- Anemone  (Actinia  marginata)  of  our  coast. 


SEA-ANEMONES  AND  COKALS. 


11 


soft  ball  rises  gradually, 
till    it     stands     up,    as 
it   does   in    the    picture 
you     see    here,  —  from 
its  summit  it  puts  out 
long   and  graceful  feel- 
ers   growing     so     close  No  g 
that    they   look    to   you    like   fringes,   forming 
a   sort   of    wreath    around 
the  top.     Very  slowly  and 
softly       these        beautiful 
fringes     creep     out     from 
the    inside     of    the    little 
animal,  where    they    have 
lain,  drawn  in.  and  pack- 
ed  away   so    snugly   that 
you  never  suspected  they  were  there,  and  then 
when  they  are  fully  spread,  they  move  gently 
up  and  down,  with  a  slow,  waving  motion. 

My  wood-cut  gives  you  no  idea  of  their 
beauty ;  you  must  imagine  them  light  colored, 
and  soft  and  delicate  as  the  down  on  a  feather. 
So  pretty  as  they  are,  and  so  soft,  you  will  hard- 
ly believe  that  they  have  attached  to  them  an 
instrument  which  is  as  dangerous  and  deadly  to 


12  SEA-ANEMONES  AND  CORALS. 

all  the  little  animals  which  the  Sea-Anemone 
likes  for  its  food,  as  the  claws  of  your  pussy  are 
to  a  mouse.  Do  you  know  what  a  lasso  is  ?  It 
is  a  long  rope  which,  in  some  countries,  is  used 
for  catching  cattle.  It  has  a  noose  at  one 
end,  and  is  carried,  coiled  up  in  the  hand, 
till  the  animal  comes  quite  near,  and  then  it 
is  thrown  suddenly  out,  and  the  men  who 
use  it  understand  how  to  cast  it  with  such 
dexterity  and  force,  that  the  noose  slips  over 
the  animal's  head  or  feet,  and  then  they  have 
him  fast  enough.  Now  the  Sea- Anemone 
has  upon  these  fringes  or  tentacles,  as  I  will 
call  them,  because  that  is  their  true  name, 
numbers  of  what  are  called  lasso-cells.  They 
are  so  small  that  you  cannot  see  them  with 
your  naked  eye,  but  each  little  cell  contains  a 
long  hollow  thread  coiled  up  in  a  spiral  within 
it.  Now  they  have  the  power  of  flinging  this 
thread  suddenly  out,  when  there  is  any  little 
shrimp  or  shell  swimming  about  in  the  water 
which  they  fancy  for  a  meal,  and  in  an  instant 
he  finds  himself  entangled  in  their  tiny  cords 
like  a  fly  in  a  spider's  web.  Little  shrimps 
swimming  near  them,  full  of  activity,  are  sud- 


SEA-ANEMONES  AND  C03ALS.  18 

denly  struck  dead  at  the  mere  contact  with 
these  poisonous  whips,  and  may  be  seen  hang- 
ing lifeless  on  the  feelers.  Here  is  the  figure  of 
a  magnified  lasso-cell,  with  the 
coil  partly  turned  out.  It  is  a 
sort  of  bag,  as  you  see,  within 
which  the  thread  is  wound  up  in 
a  spiral,  and  from  which  it  can 
be  thrown  out  in  an  instant  at 
the  will  of  the  animal.  These 
cells  are  so  small,  that  only  a 
very  powerful  microscope  will  re- 
veal them  to  the  sight,  for  they 
are  no  more  to  be  discerned  by 
the  naked  eye  than  the  separate 
stars  forming  the  Milky- Way 
can  be  distinguished  without  the  No.  4. 
aid  of  the  telescope.  When  the  prey  is  caught 
in  this  way,  the  tentacles  close  upon  it  and 
pass  it  into  the  mouth;  but  in  order  that  you 
may  understand  this,  I  must  tell  you  some- 
thing about  the  mouth,  and  about  the  inside  of 
our  little  Sea- Anemone.  If  we  look  down  upon 
him  from  above,  we  shall  see  in  the  centre  of 
the  fringes  a  hole,  and  that  hole  is  the  mouth 
which  opens  into  a  kind  of  sac  that  hangs  down 


14 


SEA-ANEMONES  AND  CORALS. 


No  5 


below  it,  inside  the  animal,  and  is  its  stomach, 

into  which  all  the 
food  passes  and 
where  it  is  digest- 
ed. If  we  could 
make  a  cut  across 
our  little  friend,  so 
as  to  get  a  glimpse 
of  his  internal 
arrangement,  we 
should  see  this  sac 
which  makes  a 
cavity  in  the  middle  of  the  body,  and  we 
should  find  that  the  rest  of  the  body  is  di- 
vided by  a  number  of  partitions,  running  from 
top  to  bottom,  and  radiating  from  this  cen- 
tral sac  to  the  outside ;  so  that  looked  at  from 
above  they  run  from  the  middle  to  the  edge  like 
the  spokes  of  a  wheel,  but  they  are  continued 
from  the  summit  to  the 
base,  thus  dividing  the 
animal  by  many  parti- 
tions. Now,  in  order 
that  you  may  under- 
stand how  he  digests 
.  6.  his  dinner,  when  he  has 


SEA- ANEMONES  AND  CORALS.  15 

caught  and  killed  it,  you  must  know  that  the 
sac  or  stomach  in  the  middle  of  the  body 
opens  by  an  aperture  in  the  .bottom  into  the 
main  body.  The  sea-water,  which  enters  free- 
ly through  the  mouth  with  the  food,  softens 
it,  helps  reduce  it  to  a  kind  of  pulp,  and  it 
passes  from  the  stomach  into  the  body,  circu- 
lating through  all  the  partitions  and  passing 
from  them  into  the  tentacles;  for  every  one  of 
the  tentacles  connects  with  one  of  the  spaces 
divided  off  by  the  partitions.  Thus  you  see 
the  whole  body  is  nourished  by  whatever  en- 
ters at  the  mouth.  On  the  inner  side  of  the 
partitions,  little  eggs  are  formed,  which  hang 
there  till  they  are  ready  to  be  hatched,  and 
then  they  pass  out  through  the  mouth,  into  the 
water,  where  they  grow  into  Sea-Anemones 
like  the  one  of  which  we  have  been  talking. 

I  hope  that  the  Sea- Anemone  has  interested 
you  so  much,  that  you  will  like  to  hear  about 
some  other  animals  of  the  same  kind,  which 
live  also  in  the  sea,  and  of  which  I  have  a 
strange  and  wonderful  story  to  tell  you, — tiny 
little  creatures,  some  of  them  no  larger  than  a 
pin's  head,  yet  they  have  built  up  large  islands, 


16  SEA- ANEMONES  AND  CORALS. 

and  even  considerable  portions  both  of  Europe 
and  America.  These  are  the  coral  animals ; 
and  though  they  do  not  live  on  our  northern 
coasts,  so  that  you  cannot  therefore  see  them 
alive,  and  are  much  smaller  than  our  Sea- Anem- 
one, yet,  as  many  of  them  are  constructed  on 
the  same  plan,  what  I  have  told  you  about  his 
tentacles,  his  partitions,  his  internal  sac,  his  lasso- 
cells,  may  help  you  to  understand  what  I  have 
to  tell  you  of  the  coral  animals.  They  do  not 
live  singly,  like  our  Sea- Anemone,  whom  we 
found  all  alone  in  his  puddle,  but  they  grow 
together  in  clusters.  Such  clusters,  however, 
start  from  a  single  little  animal  ;  it  is  born 
free,  a  little  pear-shaped,  soft  animal,  white  and 
jelly-like,  swimming  about  in  the  water.*  It 
moves  with  great  rapidity,  be- 
cause it  is  covered  all  over 
with  a  little  vibrating  fringe,f 
No.  7.  No.  8.  and  that  fringe  moves  with 
incredible  quickness,  and  keeps  the  little  Coral 
in  constant  rapid  motion.  But  when  it  finds 

*  The  young,  just  hatched,  of  Porites, —  a  Coral,  found  on  the 
Reef  of  Florida.    No.  7  seen  from  the  side;  No.  8  from  above, 
t  Vibratile  Cilia  of  Physiologists. 


SEA-ANEMONES  AND  CORALS.  17 

a  suitable  place  at  such  a  depth  in  the  sea 
as  it  likes,  and  where  the  water  is  clear  and 
bright,  for  it  does  not  fancy  muddy  or  sandy 
water,  it  attaches  itself  either  to  the  rocks  or 
the  sea-bottom  by  one  end,  which  flattens  and 
adheres  to  the  ground,  while  the  other  spreads ; 
and  the  whole  has  a  cup-shaped  form  a  little 
depressed  at  the  top.*  That  depression  marks 
where  the  mouth  is  presently  to  be,  and  be- 
fore long  it  becomes  a  hole  in  the  centre,  and 
all  around  it  feelers  or  tentacles  begin  to  ap- 
pear. You  see  by  the  picture,  that  it  looks 
very  much  like  our  Sea-Anemone,  though  it 
has  not  so  many  feelers;  but  then  the  Sea- 
Anemone,  when  young,  has  not  more.  It  is 
only  in  its  full-grown  condition,  that  it  has 
the  numerous  tentacles  which  the  picture  rep- 
resents. The  sides  of  the  coral  animal  begin 
to  thicken,  the  sac  which  is  the  stomach  forms 
in  the  centre,  and  also  the  partitions  dividing 
the  rest  of  the  body.  If  we  could  make  a 
cut  across  the  little  Coral,  we  should  see  that 
he  is  formed  inside  like  our  Sea- Anemone  ; 
we  should  see  the  cavity  in  the  centre  formed 

#  The  same  as  wood-cut  7,  seen  from  above. 
2 


18  SEA-ANEMONES  AND  CORALS. 

by  the  stomach,  and  the  partitions  spreading 
from  it  like  the  spokes  of  a  wheel.  But  I 
must  explain  to  you  a  very  important  differ- 
ence between  them  and  the  Anemone,  which 
will  help  you  to  understand  the  long  story  I 
have  to  tell  you  about  these  wonderful  little 
animals,  who  play  such  an  important  part  in 
the  history  of  the  world. 

We  have  seen  that  our  little  Sea- Anemone 
is  soft  throughout,  —  he  is  just  like  a  mass  of 
jelly,  and  though  the  parts  of  his  body  are 
quite  distinct,  yet  his  partitions,  his  tentacles, 
the  walls  of  his  body,  and  the  sac  serving  him 
as  a  stomach,  are  all  quite  soft,  and  he  can 
change  his  form,  contract  all  his  parts,  and  roll 
himself  up  like  a  little  ugly  lump,  just  for  the 
reason  that  the  whole  of  his  substance  is  pul- 
py and  gelatinous.  But  with  the  Coral  it  is 
quite  different.  It  is  true  that  when  he  is  first 
born,  he  is,  as  I  have  described  him,  a  little, 
oval,  jelly-like  animal,  swimming  about  in  the 
water ;  but  after  he  has  selected  his  resting- 
place,  has  grown  larger,  and  his  mouth,  his 
stomach,  the  partitions  of  his  body  and  his  ten- 
tacles are  formed,  then  begins  a  process  which 


SEA- ANEMONES  AND  CORALS.  19 

ends  in  giving  him  a  very  different  character 
from  that  of  the  Anemone.  There  are  hard 
particles  of  lime  in  his  substance,  and  these 
accumulate,  first  at  the  base  of  the  body,  where 
it  is  attached  to  the  ground,  so  that  it  becomes 
quite  firm  and  solid,  then  in  all  the  partitions, 
so  that  they  become  like  little  solid  walls,  and 
in  the  sides  of  the  body,  so  that  they  too  grow 
quite  hard ;  and  now  the  whole  has  a  solid 
frame,  the  only  parts  of  the  little  creature  which 
remain  soft,  being  the  summit,  the  mouth,  the 
fringes  around  it,  and  the  stomach  within. 

I  have  said  that  the  coral  animals  grow  in 
clusters,  but  thus  far  I  have  only  described  the 
single  animal  that  begins  the  coral  stock.  Now 
I  will  show  you  how  he  mul- 
tiplies himself,  till,  instead  of 
one  animal  there  are  count- 
less  multitudes  living  together 
in  one  community.  The  ad- 
joining figure  shows  you  a 
part  of  such  a  community.* 
When  the  first  coral  animal 

No.  9. 

has  undergone  the  changes  I 

*  A  branch  of  full-grown  Porites  in  natural  size. 


20 


SEA-ANEMONES  AND   CORALS. 


have  described,  and  assumed  its  permanent 
character,  it  begins  to  spread  and  grow  taller, 
and  from  its  surface,  either  from  the  base 
or  from  the  sides,  grow  up  other  animals  of 
the  same  kind,  remaining  always  attached  to 
the  first,  and  increasing  till  they  are  crowded 
together  in  hundreds  and  thousands  and  mill- 
ions on  one  foundation.  This  way  of  grow- 
ing is  called  budding,  because  it  resembles  a 
little  the  branching  of  a  plant,  but  each  bud 
is  nothing  but  a  new  animal,  remaining  con- 
nected with  the  preceding  as  the  branches  of 
a  tree  with  the  stem. 

The  various  kinds  of  Corals  grow  in  differ- 
ent ways  and 
vary  greatly  in 
size,  some  be- 
ing no  larger 
than  a  pin's 
head.  Some 
bud  from  the 
base,  as  in 
the  figure 
which  you  see 
•  -  "TJPP^  in  wood-cut 

No.  10. 


SEA- ANEMONES  AND  CORALS.  21 

10 ;  *  others  from  the  side,  as  in  our  little 
picture  here  ;  f  in  oth- 
ers, each  animal  widens 
gradually  toward  the 
summit  as  it  grows, 
assuming  thus  a  sort 
of  trumpet  shape,  then 
divides  so  that  where 
there  was  but  one 
mouth,  there  are  now 

two,  as  you  see  in  the  picture, $  and  these  again 
may  spread  and  divide 
in  the  same  manner,  so 
that  the  cluster  goes 
on  increasing  in  that 
way,  one  animal  di- 
viding into  two  or 
more,  till  they  become 
a  cluster.  In  another 
kind,  the  individuals  No.  12. 

do  not  divide  and  widen  as  they  grow  higher, 
and  cannot  therefore,  by  spreading,  fill  up  the 
spaces  between,  which  enlarge  with  their  in- 

*  Agaricia  or  Mycidium.  f  Caryophyllia. 

Mussa. 


22  SEA-ANEMONES  AND  CORALS. 

creasing  height;  but  in  those  spaces  the  new 
buds  form,  thus  filling  all  the  intervals,  and 
making  a  coral  mass  covered  all  over  with 
thousands  of  closely  packed  pits,  which  mark 
the  spots  occupied  each  by  a  little  animal.* 
Others  grow  in  lighter 
branches,  so  like  plants 
that  I  am  sure,  if  you 
looked  into  water  where 
numbers  of  these  sin- 
gular animals  were  grow- 
ing in  the  sea,  wav- 
ing their  branches  to 
No- 13>  ;and  fro,  like  an  ocean 

shrubbery,  you  would  suppose  they  were  gi- 
gantic but  exquisite  sea- weeds,  rather  than 
living  beings.  On  these  branches  are  crowded 
thousands  of  these  little  creatures,  living  a 
common  life,  and  building  up  coral  groves 
under  the  water.  Here  you  have  a  little 
picture  of  one  commonly  called  the  Sea-Fan,f 
which,  -when  living,  is  particularly  beautiful,  on 
account  of  its  ornamented  tentacles.  They  not 

*  Astrea:  heads  of  this  kind  measure  frequently  several  feet 
across. 

t  No.  14  —  Gorgonia. 


SEA-ANEMONES  AND  CORALS. 


23 


only  form  a  fringe  around 
the  summit  of  the  animal, 
but  they  are  themselves 
fringed,  or  lobed,  along 
their  edges.  The  wood- 
cut represents  only  a  small 
branch,  but  they  grow  to 
the  height  of  several  feet. 
Among  the  branching 
Corals,  there  is  one  kind, 
the  so-called  Finger  Cor- 
al,* which  differs  from  the 
others  in  having  a 
somewhat  larger  ani- 
mal on  the  top  of 
each  branch,  with 
smaller  ones  all 
around  the  stem  and 
branches.  They  rep- 
resent, as  it  were,  the 
patriarchal  heads  of 
the  family,  occupy- 
ing the  seat  of  honor 
at  the  summit  of 


No.  14. 


No.  15. 


Madrepora. 


24  SEA-ANEMONES  AND  CORALS. 

every  branch,  while  the  little  ones  grow  around 
and  below  them. 

I  dare  say  you  have  seen  specimens  of  Cor- 
als, because  they  are  so  beautiful  that  all  who 
travel  to  the  tropical  oceans  where  they  grow, 
—  to  the  coast  of  Florida,  to  the  Pacific,  and 
the  East  Indies,  —  bring  home  specimens  of 
them.  But  when  we  see  them  at  home,  as 
they  are  brought  from  foreign  lands,  we  must 
remember  that  all  the  soft  and  moving  parts, 
the  tentacles  or  fringes  that  wave  so  grace- 
fully in  the  water,  are  gone  ;  for  they  decay 
when  the  animal  dies,  and  nothing  remains 
but  the  hard  frame  which  I  have  described 
to  you.  Notwithstanding  this,  however,  we 
can  see  in  such  a  mass  of  dead  Coral  the 
spot  where  every  little  animal  has  lived.  Some 
of  them  form  round  masses  which  are  called 
coral  heads.  Such  coral  heads  differ  in  ap- 
pearance according  to  the  method  of  grow- 
ing of  the  coral  animal  by  which  they  were 
formed.  In  a  dead  coral  mass,  for  instance, 
made  by  those  animals  which  have  the  trum- 
pet shape,  and  which  increase  by  spreading 
and  dividing,  the  marks  that  are  left  are  more 


SEA-ANEMONES  AND   COEALS.  25 

uneven,  forming  undulating  lines  on  the  sur- 
face.* In  that  which 
does  not  widen  as  it 
grows,  but  in  which 
the  spaces  are  filled 
by  the  budding  of 
new  animals,  the  holes 
are  quite  regular,  and 
have  a  star-shaped 
figure,  (see  wood-cut 
No.  13,)  produced  by 
the  partitions  arranged  No.  IG. 

like  the  spokes  of  a  wheel,  as  I  have  described 
them  to  you  in  the  single  little  Coral  and  in 
the  Sea- Anemone.  All  Corals  of  the  kinds  I 
speak  of  are  formed  in  this  way,  whether  they 
grow  in  branches  or  in  round  masses,  whether 
they  bud  from  the  base  or  from  the  side,  or 
increase  by  division ;  the  structure  of  every 
separate  little  animal  is  the  one  that  I  have 
tried  to  explain  to  you. 

Persons  who  have  not  had  an  opportunity 
of  watching  the  Corals  when  alive,  and  have 
only  seen  the  dry  coral  heads  with  their  reg- 

*  Meandrina. 


26  SEA-ANEMONES  AND  CORALS. 

ular  pits  throughout,  often  talk  of  coral  in- 
sects as  building  the  Corals,  comparing  them 
to  the  bee  that  builds  its  honeycomb.  But 
this  is  not  correct.  There  are  no  coral  in- 
sects, for  insects  are  entirely  different  from 
the  coral  animals,  and  the  hard  Coral  is  com- 
posed of  the  solid  frame  of  the  animals  them- 
selves, their  skeletons  as  it  were,  instead  of 
being  a  structure  which  they  build  to  live  in, 
as  the  bee  builds  its  honeycomb.  The  honey- 
comb is  truly  a  kind  of  house  the  bee  con- 
structs for  itself,  to  live  in  and  to  lay  its  eggs 
in,  and  to  fly  out  of  and  into  at  will.  But  the 
cells  in  a  coral  head  are  a  part  of  the  coral 
animals  themselves,  and  though  they  can  with- 
draw their  soft  parts  into  their  solid  frame,  or 
expand  them  at  will,  they  cannot  be  separated 
from  it,  for  it  is  as  necessary  to  their  life,  and 
as  much  a  part  of  it,  as  our  bones  are  a  part 
of  our  bodies. 

There  is  one  thing  I  have  not  told  you 
about  these  animals,  and  that  you  will  think 
very  odd  in  their  way  of  living.  They  are 
all  connected  with  each  other,  the  body  of 
each  one  opening  at  its  base  into  that  of  the 


SEA-ANEMONES  AND  CORALS.  27 

next,  so  that  what  enters  in  at  the  mouth  of 
one,  after  circulating  in  his  body,  passes  into 
the  next,  and  thus  you  see  when  one  eats  his 
dinner,  it  nourishes  not  only  himself,  but  all 
his  neighbors  too. 


28  CORAL  REEFS. 


t      CHAPTER   II. 
CORAL   REEFS. 

I  HAVE  told  you  that  these  strange  little 
beings  have  built  up  large  islands  and  parts  of 
continents,  and  I  hope  with  what  I  have  said 
of  their  way  of  growing,  of  their  solid  frame, 
and  of  their  living  in  such  crowded  communi- 
ties, forming  large  hard  masses,  you  will  be 
able  to  understand  how  these  busy  little  ani- 
mals, who  in  order  to  fulfil  their  appointed 
work  have  only  to  grow,  have  helped  to  make 
the  world. 

"We  will  suppose  that  under  the  level  of 
the  ocean  there  is  an  island  or  a  rocky  hill 
growing  up  from  the  bottom  of  the  sea,  which, 
if  it  became  large  and  high  enough  to  be  seen 
above  the  water,  would  be  what  we  call  an 


CORAL  REEFS.  29 

island.  Perhaps  you  think  of  the  bottom  of  the 
ocean  as  one  great  level  floor,  —  I  remember  I 
did,  when  I  was  a  little  girl ;  but  in  the  ocean, 
as  well  as  on  land,  there  are  hills  and  valleys, 
and  even  mountain  chains.  Suppose  then  that 
there  were  an  elevation  under  the  sea  which,  if 
it  rose  higher  than  the  water,  would  be  an  isl- 
and, but  which  stops  at  a  depth  of  ten  fathoms 
below  the  surface.  Here  we  have  its  picture. 
Now  fancy  that 
some  of  those 


'''IIIMnllfl'ilH'''" 


^%l!IWilil!ffiiP'lll|!!! 


little  coral  ani- 
mals I  have 
described  as  No.  17. 

swimming  about  freely  in  the  water  when 
they  are  first  born,  should  attach  themselves 
upon  the  side  of  this  island  and  should  begin 
to  bud  and  spread  in  large  coral  heads  all 
around  it.  We  must  remember  that  it  is  not 
only  by  budding  that  they  increase,  but  also 
by  eggs,  which  when  hatched  are  the  little 
pear-shaped  free  Corals  which  float  about  for 
a  while,  and  then  fasten  themselves  upon  the 
community,  so  that  they  not  only  multiply  by 
dividing  and  branching,  but  also  by  the  ad- 


30  CORAL  REEFS. 

dition  of  all  the  little  animals  that  are  born 
from  their  eggs.  As  this  coral  bank  grows, 
the  lower  ones  gradually  die,  their  solid  frames 
still  remaining  to  form  a  firm  foundation  for 
all  that  grow  above  them.  All  the  cracks  and 
crevices  are  filled  with  sand,  bits  of  shell,  &c., 
so  that  it  makes  a  wall  as  strong  as  any 
masonry.  When  they  have,  by  their  growth, 
formed  a  ridge  all  around  the  island,  they 
begin  to  grow  upward  from  the  foundation 
which  they  have  laid,  thus  raising  a  circular 
wall  about  it.  But  when  they  have  reached  a 
certain  height  in  the  water,  those  Corals,  which 
like  deep  water,  will  no  longer  grow  there,  and 
they  die  out ;  but  on  the  surface  that  they 
have  prepared,  new  kinds,  which  like  the  shal- 
low water,  begin  to  establish  themselves,  and 
they  continue  the  wall  the  others  had  begun. 
As  it  goes  on  increasing  in  height,  these  also 
find  the  water  too  shallow  for  them,  but  now 
to  complete  the  work  come  in  the  branching 
ones,  which  I  have  described  to  you  as  resem- 
bjing  sea-weeds  and  plants,  and  so  the  wall  is 
crowned  by  a  waving  shrubbery.  This  brings 
it  at  last  to  the  surface  of  the  water ;  and  now 


CORAL  REEFS.  31 


^^PiP™^  ^™1!MMI 


our  island  is  surrounded  by  a  circular  wall,  ris- 
ing to  the  level 
of  the  sea.  But 
above  that  no 
Corals  can  live, 
and  therefore  as  No- 18- 

soon  as  the  wall  rises  above  high-water  mark, 
the  work  of  the  little  builders  is  done,  —  they 
can  bring  it  up  no  higher,  and  they  die  for 
want  of  the  constant  action  of  the  sea-water. 
But  now  other  influences  come  in  to  complete 
the  structures.  The  waves  beating  against  the 
coral  wall  wear  away  its  surface,  break  off  large 
pieces  from  it  by  constant  rolling  and  grinding, 
wear  them  into  sand,  and  in  storms  these  bro- 
ken masses  of  coral  rock,  and  quantities  of  coral 
sand  are  thrown  up  on  the  top  of  the  wall. 
Gradually  all  the  scattered  materials  floating  in 
the  sea  around  settle  upon  it,  and  the  summit 
becomes  covered  with  a  soil  composed  of 
broken  coral  masses,  sand,  mud,  parts  of  shells, 
drifted  sea-weed,  &c.  And  now  perhaps  birds 
drop  there  the  seeds  of  some  plant,  or  such 
seeds  are  floated  from  some  neighboring  shore, 
— trees  spring  up  there,  flowers  and  grass  grow 


32  CORAL  REEFS. 

upon  it,  —  men  come  and  settle  there,  —  they 
build  their  houses  and  plant  their  gardens  on 
our  circular  island,  which  lies  like  a  green  ring 
on  the  sea  and  incloses  within  it  a  calm  ocean 
lake.  And  so  you  see  these  tiny  creatures, 
many  of  them  no  larger  than  a  pin's  head, 
build  up  from  the  ocean  depths,  lands  that 
may  grow  green  and  luxuriant  with  the  beau- 
tiful vegetation  of  the  tropics  and  in  which  men 
may  find  a  pleasant  home. 

I  should  tell  you  that  all  coral  structures, 
while  the  Corals  are  building  them,  and  before 
they  are  transformed  into  land,  are  called  reefs. 
I  have  spoken  of  the  circular  one  which  I  have 
been  describing  as  a  wall,  because  I  thought 
you  would  understand  my  meaning  better ;  and 
they  are  truly  walls.  But  the  common  name 
for  them  is  reef,  and  the  coral  animals  are 
called  reef-builders. 

There  are  other  kinds  of  islands  which  are 
built  by  Corals ;  sometimes  they  build  around 
an  island  which  rises  above  the  level  of  the  sea, 
and  then,  of  course,  the  centre  is  filled  with 
solid  land,  instead  of  being  a  lake  inclosed  by 
the  coral  growth,  as  in  the  one  I  have  been 


CORAL  REEFS. 


33 


describing.  The  circular  ones  we  have  been 
talking  about,  are  Lagoon  Islands.  There  are 
many  of  them  in  the  Pacific  Ocean.  When 
people  first  made  voyages  in  the  Pacific  Ocean, 
they  could  not  at  all  understand  the  meaning  of 
these  islands,  formed  like  rings,  with  calm  water 
in  their  centre.  Usually  when  the  islands  are 
large,  they  do  not  close  completely,  but  some- 
times one  or  more  gaps  are  left  in  the  ring, 
through  which  vessels  can  pass  in,  and  anchor 
in  the  quiet  harbors  formed  within  the  shelter 
of  these  coral  banks  with  the  trees  that  grow 
upon  them.  You  may  imagine  how  surprised 
voyagers  must  have  been,  when  they  first 
sailed  through  such  an  opening  in  a  circular 
coral  island  and  found  themselves  in  a  quiet 
lake  in  mid- 
ocean.  Some- 
times  these 
coral  structures 
are  made  into 
Lagoon  Islands 
by  the  sinking 
of  the  land  around  which  they  have  begun 
to  grow.  Suppose,  for  instance,  that  Corals 


No.  19. 


34  CORAL  REEFS. 

establish  themselves  around  an  island,  and  the 
island  gradually  subsides  below  the  level  of 
the  sea,  as  islands  are  often  known  to  do  in 
the  Pacific  Ocean ;  the  Corals  continue  to  grow 
upward  as  the  island  continues  to  sink,  and  by 
the  time  the  Corals  reach  the  level  of  the  sea, 
the  island  is  out  of  sight,  nothing  being  visible 
but  the  ring  of  coral  bank,  with  water  in  the 
middle. 

I  have  told  you  that  not  only  are  islands 
built  up  by  Corals,  but  parts  of  continents  also ; 
and  I  will  show  you  how  the  whole  peninsula 
of  Florida  has  been  patiently  added  to  the  con- 
tinent of  North  America  on  which  you  live,  by 
these  busy  little  reef-builders,  during  so  many 
thousand  years,  that  you  would  find  it  difficult 
to  count  the  centuries. 

Do  you  remember  how  Florida  is  shaped  and 
situated,  like  a  long  tongue  of  land  running  out 
into  the  Gulf  of  Mexico  ?  Here  is  a  picture 
of  it.  Outside,  at  a  little  distance,  you  see, 
there  are  a  number  of  islands,  called  Keys,  lying 
in  a  curved  line  around  it,  and  about  five  miles 
beyond  these  islands,  if  you  could  look  below 
the  water,  you  would  see  a  crescent  shaped  wall 


CORAL  REEFS. 


35 


growing  up  from  the  sea-bottom ;  but  as  yet  it 
rises  to  the  surface  of  the  water  only  in  two  or 
three  spots,  and  then  only  as  points  of  rock, 
where  light-houses  and  beacons  are  placed  to 
warn  away  vessels  ;  for  if  a  ship  drives  in  upon 
that  treacherous  wall  beneath  the  water,  she 
may  be  broken  to  pieces.  Can  you  fancy  who 


36  CORAL  REEFS. 

has  been  building  that  wall  ?  I  think  you  will 
say  at  once  that  here  also  our  little  masons  of 
the  sea  have  been  at  work, — and  so  it  is.  The 
Coral-builders  have  been  erecting  that  wall,  but 
though  they  have  been  at  work  upon  it  for 
many  thousand  years,  they  have  not  yet  suc- 
ceeded in  bringing  it  to  the  sea-level,  except  at 
two  or  three  points,  as  I  have  mentioned.  They 
are  not  however  discouraged, — they  are  far 
more  patient  than  little  boys  and  girls,  —  more 
patient  even  than  men, — and  they  will  go  on, 
adding  little  by  little  to  their  wall,  till  they  have 
joined  it  to  the  mainland  of  Florida. 

But  they  cannot  do  this  all  alone,  —  other 
agencies  must  help  them ;  and  in  order  to 
understand  how  this  is,  we  must  look  a  little 
at  those  islands  lying  within  the  outer  wall, 
and  at  the  space  that  divides  them  from  the 
mainland.  Those  islands  are  part  of  a  coral 
wall  exactly  like  the  one  outside  of  them,  be- 
low the  water,  and  the  islands  are  those  parts 
of  it  which  have  reached  the  surface,  and  on 
which  a  soil  has  been  formed  by  the  collec- 
tion of  sand,  mud,  broken  shells,  coral,  sea- 
weed, &c.  There,  as  on  the  circular  islands  of 


CORAL  REEFS.  37 

the  Pacific,  trees  and  flowers  grow,  and  people 
live,  and  if  you  were  to  see  some  of  the  beau- 
tiful gardens  of  Key  West, — the  name  of  one 
of  these  islands, — with  their  tropical  flowers  of 
the  most  brilliant  hues,  their  cocoa-nut  trees, 
their  banana  trees,  and  their  delicious  fruits,  and 
the  pleasant  houses  that  stand  in  the  midst  of 
all  this  beauty,  you  would  hardly  believe  that 
on  this  spot,  not  very  long  ago,  the  waves 
washed  over  the  little  Coral-builders.  There 
are,  as  you  see  by  the  wood-cut,  several  of  these 
islands,  all  formed  in  the  same  way,  by  those 
parts  of  the  inner  coral  wall,  that  have  risen 
above  the  surface  and  have  become  covered 
with  soil.  Between  these  islands  and  the  main- 
land, the  present  coast  of  Florida,  all  the  space 
is  filled  by  mud  flats, — that  is,  by  a  large  col- 
lection of  mud,  formed  by  the  washing  of  the 
sea  against  the  shore  and  against  the  coral  reef 
wearing  it  into  sand  and  mud,  which  has  been 
heaped  up  in  the  channel  between  the  line  of 
islands  and  the  shore,  till  it  fills  it  completely. 

I  think  that,  with  these  facts,  we  can  see 
how,  in  the  course  of  many  years,  the  solid 
land  of  Florida  will  extend  to  where  that  outer 


38  CORAL  REEFS. 

coral  wall  now  runs  beneath  the  surface  of  the 
water.  The  mud  flats  will  increase  by  the  con- 
stant addition  of  all  the  mud,  sand,  broken 
shells,  and  materials  of  all  sorts,  that  float 
about  in  the  channel  between  the  coast  and 
the  islands,  till  they  are  raised  to  a  level  with 
them,  and  connect  them  by  solid  ground.  The 
wall,  of  which  the  islands  are  only  those  parts 
that  have  grown  more  rapidly  here  and  there, 
will  complete  its  growth,  and  rise  above  the 
level  of  the  sea  for  its  whole  length.  The  outer 
reef,  now  rising  only  in  two  or  three  rocky 
points  above  the  sea  level,  will  gradually  form 
islands  here  and  there,  as  the  inner  one  now 
does,  and  between  those  islands  and  the  inner 
reef,  which  will  then  be  the  coast  of  Florida, 
mud  flats  will  collect  and  fill  the  space.  The 
outer  reef  will  then  gradually  complete  its 
growth,  no  longer  remaining  a  series  of  islands, 
but  becoming  a  long  strip  of  land ;  the  mud  flats 
will  unite  it  to  the  inner  one,  and  then  there 
will  be  solid  ground  all  the  way  from  the 
present  coast  of  Florida  to  where  the  outer 
coral  reef  now  runs  beneath  the  sea. 

This  will  take  place  in  centuries  to  come ; 


CORAL  REEFS.  39 

but  it  actually  has  taken  place,  to  the  north  of 
the  present  reefs,  during  thousands  of  years 
past,  and  the  whole  peninsula  of  Florida  has 
been  formed  by  the  same  process  that  is  going 
on  at  its  southern  extremity  now.  All  that  part 
of  Florida  which  has  been  examined  is  found 
to  be  formed  in  this  way,  first  a  reef  and  then 
a  mud  flat,  and  then  a  reef  and  then  a  mud 
flat,  one  within  the  other,  just  as  they  lie  now 
at  the  southern  end.  Seven  such  reefs  and 
mud  flats  have  been  discovered  already,  and  I 
suppose  there  are  many  more  in  the  northern 
part.  Of  course,  without  digging  down  below 
the  surface  and  studying  the  formation  of  the 
ground,  we  could  not  detect  this,  because  for 
centuries  all  traces  of  those  old  reefs  and  mud 
flats  have  been  covered  with  soil  and  grass  and 
trees  and  flowers.  We  should  no  more  sus- 
pect, from  its  present  appearance,  that  Florida 
had  once  been  the  ocean  home  of  the  reef- 
builders,  than  the  people  who  live  centuries 
after  us  will  suspect  that  what  will  then  be  its 
southern  extremity,  was,  in  our  time,  almost 
entirely  under  water. 

You  may  ask  why  the  little  Corals  do  not  set- 


40  CORAL  REEFS. 

tie  nearer  the  shore,  and  connect  their  reef  im- 
mediately with  it,  instead  of  beginning  at  a 
distance  of  three  or  four  miles  from  the  shore, 
thus  leaving  a  channel  to  be  filled  up  afterwards 
by  mud  flats.  The  reason  is  this.  The  Corals 
which  form  the  foundation  of  the  reef  delight 
in  deep  water,  and  could  not  live  in  the  shallow 
waters  of  a  sloping  shore,  and  they  like  also 
perfectly  clear  water,  untroubled  by  the  mud 
and  sand  washed  off  from  the  land  by  the 
waves.  They  naturally  seek  the  conditions 
most  favorable  for  their  growth,  and  establish 
themselves  at  a  little  distance  from  the  coast, 
where  they  find  the  deep,  untroubled  waters 
which  they  need. 

There  are  other  kinds  of  Corals  beside  those 
that  I  have  described  here,  —  some  that  are 
vegetable,  a  kind  of  stony  sea-weed,  as  it  were, 
growing  hard  from  the  quantity  of  lime  par- 
ticles it  contains ;  and  others  which,  like  those 
we  have  been  speaking  of,  are  little  animals, 
differing  somewhat  from  them,  however,  in  the 
arrangement  of  their  parts.  But  it  is  not  ne- 
cessary, in  order  that  you  should  understand 
the  building  of  a  coral  reef,  to  explain  to 


COKAL  REEFS.  41 

you  the  different  nature  of  all  the  Corals  that 
compose  it. 

Florida  is  not  the  only  country  that  has  been 
built  up  in  this  way.  One  of  the  most  beauti- 
ful parts  of  Switzerland,  called  the  Jura,  lying 
on  the  border  between  Switzerland  and  France, 
is  formed  of  coral  reefs  such  as  are  now  form- 
ing in  Florida.  If  you  look  at  your  map  of 
Europe,  you  will  see  what  great  changes  must 
have  taken  place  since  then.  Now  you  see 
Switzerland  is  completely  shut  out  from  the 
sea ;  it  lies  between  France,  Germany,  Austria, 
and  Italy,  and  is  land-locked  on  every  side. 
But,  as  we  know  that  Corals  can  only  live  in 
the  sea-water,  it  is  evident  that  in  the  days 
when  they  were  building  up  the  Jura,  the  ocean 
must  have  washed  the  shores  of  Switzerland 
on  its  western  side,  and  the  southern  part  of 
France  cannot  have  existed  at  all. 


The  structure  which  I  have  described  to  you 
in  the  Sea- Anemone  and  the  Coral,  belongs  to 
many  other  little  beings  having  their  home  in 


42  CORAL  REEFS. 

the  sea,  and  all  animals  so  constructed  are 
called  Polyps.  That  is  their  scientific  name, 
and  it  includes  thousands  of  animals  which, 
however  they  may  differ  in  external  form,  have 
their  parts  arranged  internally  in  the  same  way. 


HYDROIDS  AND  JELLY-FISHES.  43 


CHAPTER  III. 
HYDROIDS  AND  JELLY-FISHES. 

OUR  walk,  beginning  at  Nahant,  has  ex- 
tended rather  far,  —  has  it  not?  Let  us  come 
back  now  from  Florida  and  the  Corals,  and 
the  strange  old  times  when  the  reef-builders 
were  contributing  their  share  toward  one  of 
the  most  beautiful  countries  in  the  world,  and 
see  what  else  we  can  find  that  is  interesting 
among  the  animals  living  close  about  our 
own  home. 

In  many  of  the  pools  left  by  the  retreating 
tide  along  our  beaches  and  rocks,  —  such  as 
that  in  which  we  found  our  Sea- Anemone,  we 
may  find  little  animals  resembling  flowers  even 
more  than  that  does,  because  they  grow  in 
clusters  like  miniature  shrubs.  Here  we  have 


44 


HYDROIDS  AND  JELLY-FISHES. 


No  21. 


a  picture  of  one.*  You 
will  hardly  believe  that 
it  is  built  on  the  same 
general  plan  as  the 
Anemone,  when  its  ap- 
pearance is  so  different, 
but  you  will  soon  learn, 
if  you  watch  animals,  that 
their  external  form  may 
differ  very  much,  and  yet 
that  they  may  be  con- 
structed according  to  the 
same  plan.  If  we  examine  each  of  these  little 
animals,  hanging  like  flowers  at  the  summit 
of  each  slender  stalk,  we  shall  find  that  they 
have  many  of  the  features  belonging  to  the 
Anemone  and  to  the  Coral.  They  have  the 
wreath  of  tentacles,  looking  like  a  fringe 
around  the  mouth,  and  the  mouth  opens  into 
a  cavity  in  the  middle,  which  is  the  stomach ; 
but  they  have  not  the  partitions  that  in  the 
Sea- Anemone  and  the  Corals  divide  the  rest  of 
the  body  into  separate  parts  ;  nor  is  the  stomach 
a  sac  hanging  within  the  body,  as  in  the  Sea- 

*  Tubularia. 


HYDROIDS  AND  JELLY-FISHES.  45 

Anemone,  but  it  is  a  cavity  hollowed  out  of 
the  substance  of  the  body.  If  we  look  at  the 
slender  stalk  with  a  microscope,  we  shall  find 
that,  instead  of  a  stalk,  it  is  a  hollow  tube, 
connecting  with  the  central  stem,  which  is 
also  hollow.  In  this  community  of  animals, 
as  in  the  coral  community,  each  one  is  con- 
nected with  the  next  by  these  stems,  so  that 
all  the  water  and  food  that  enters  in  at  the 
mouth  of  one,  feeds  all  the  rest. 

There  is  one  very  odd  thing  about  these  little 
animals ;  the  young  that  are  born  from  them 
are  quite  different  from  themselves.  You  know 
that  usually  the  young  of  animals  are  like 
the  parents.  From  the  eggs  in  our  hens' 
nests,  chickens  are  hatched ;  from  the  pretty 
blue  eggs  in  the  robin's  nest,  come  forth  the 
little  robins ;  and  I  think  you  must  remember 
the  funny  little  turtles  that  came  out  of  the  tur- 
tles' eggs,  which  we  kept  in  a  box  of  earth  two 
summers  since,  to  see  what  would  become  of 
them.  We  should  naturally  suppose,  then,  that 
from  these  little  Animals  which  I  have  been  de- 
scribing, there  would  be  born  animals  like  them- 
selves, just  as  chickens  are  born  from  hens'  eggs, 


46 


HYDROIDS  AND  JELLY-FISHES. 


No.  22. 


robins  from  robins'  eggs,  and  tortoises  from  tor- 
toises' eggs.  But  we  shall  see  that  this  is  not  so. 
We  will  suppose  that  we 
have  carried  home  one  of  these 
little  clusters,  differing  some- 
what from  the  preceding,  and 
put  it  in  our  Aquarium.  Here 
you  have  its  picture.*  A  day 
or  two  after  we  may  find 
swimming  about  in  the  water 
a  little,  fairy  like,  transparent 
thing,  so  slight  and  delicate 
indeed  that  it  seems  almost 
as  if  some  drops  of  the  water 
had  taken  form  and  shape, 
and  that  this  strange  little 
being,  that  is  darting  about 
in  it,  were  but  a  part  of  the 
element  in  which  it  floats.f 
In  shape  it  is  like  a  tiny  cup 
turned  upside  down ;  from  the 
lower  side  hang  four  long 
threads ;  in  the  centre  of  the 
lower  side  hangs  a  proboscis, 
No.  23.  tne  enc*  °f  which  is  the 

*  No.  22,  Coryne.  t  No.  23,  Sarsia. 


HYDROIDS  AND  JELLY-FISHES.  47 

mouth,  and  four  tubes  run  from  the  summit 
of  the  upper  side  to  the  lower  edge,  where 
a  circular  tube  unites  them  all  around.  It 
seems  to  delight  in  its  life,  —  it  shoots  through 
the  ,  water  in  every  direction,  and  appears 
to  move  by  breathing,  for  every  motion  is 
made  by  a  sudden  contraction  and  expan- 
sion, which  is  in  truth  produced  by  the  tak- 
ing in  and  throwing  out  of  water  under  the 
cup.  Up  and  down,  and  on  every  side  it 
darts  about,  and  no  bird  can  enjoy  its  flight 
through  the  air  more  than  this  animal,  which 
scarcely  seerns  to  have  a  material  body,  so 
frail  and  unsubstantial  is  it,  appears  to  enjoy 
its  freedom  of  motion  through  the  water.  It 
is  perfectly  transparent;  a  drop  of  water,  a 
bubble  of  air,  a  spider's  web,  a  fly's  wing, 
anything  that  has  form  and  shape  at  all,  can 
hardly  be  more  slight  in  texture  than  this 
little  creature.  And  this  is  the  being  pro- 
duced from  the  cluster  of  animals,  so  different 
from  itself,  which  we  brought  in  and  placed  in 
our  Aquarium.  If  our  eyes  had  been  sharp 
enough,  or  we  had  been  in  the  habit  of  using 
the  microscope,  we  might  have  seen  that,  very 


48 


HYDROIDS  AND  JELLY-FISHES. 


near  the  tentacles  around  the  mouth  of  each 
one  of  the  little  animals,  were  hanging  bunches 
of  little  spheres.*  These 
are  buds,  quite  different 
from  the  buds  of  the  stem, 
and  from  them  are  born 
the  singular  little  creatures 
such  as  the  one  I  have 
just  described. 

Let  us  watch  him  now 
for  a  while,  and  see  what 
becomes  of  our  fairy  friend. 
NO.  24.  From    the    centre   of   the 

lower  side  hangs  down,  as  I  have  said,  a  kind 
of  proboscis,  (see  wood-cut  23.)  I  use  that 
word,  because  it  is  the  one  used  by  natural- 
ists to  describe  the  thing ;  but  I  hope  it  will  not 
remind  you  of  an  elephant's  proboscis,  which  I 
suppose  is  the  only  connection  you  have  ever 
heard  the  word  used  in.  If  you  ever  exam- 
ine the  almost  imperceptible  and  transparent 
organ  attached  to  this  little  creature,  called 
by  naturalists  a  proboscis,  you  will  wonder 

*  No.  24.  Ahead  of  Coryne  magnified,  of  which  a  great  many  are 
clustered  together  in  wood-cut  22,  where  they  are  shown  in  natural 
size. 


HYDROIDS  AND  JELLY-FISHES.  49 

that  the  same  name  should  be  used  to  describe 
two  things,  one  of  which  is  so  delicate,  and 
belongs  to  such  a  slight  and  transparent  ani- 
mal, while  the  other  is  so  heavy,  and  belongs 
to  one  of  the  largest  and  clumsiest  animals  liv- 
ing. Along  this  proboscis,  little  spheres  are 
scattered,  which  are  eggs.  From  these  eggs  are 
born  little  pear-shaped  bodies,  very  like  those 
which  I  have  described  to  you  as  the  single 
coral  animal  (see  wood-cut  7)  before  it  has 
grown  into  a  coral  stock.  It  swims  freely  about 
for  a  while,  then  becomes  attached  to  some  shell 
or  sea-weed  or  stone,  puts  out  first  a  few  tenta- 
cles,* then  gradually  more,  then  buds 
from  the  base  and  from  the  side,  and 
grows  at  last  into  a  cluster  of  animals, 
a  little  shrub,  like  the  one  with  which 
we  began.  So  you  see,  with  this  No.  25. 
animal,  it  is  not  the  child  that  resembles  the 
parent,  but  the  grandchild  that  resembles  the 
grandparent,  and  we  must  go  through  two  gen- 
erations before  we  come  again  to  the  form  with 
which  it  started. 

The  little  animals  which  grow  in  clusters  are 

*  Young  Hydroid  of  Coryne. 
4 


50  HYDROIDS   AND  JELLY-FISHES. 

all  called  Hydroids,  though  there  are  a  great 
variety  of  them  distinguished  from  each  other 
by  special  names,  with  which  I  will  not  bur- 
den your  memory  now.  Those  which  are  born 
from  them  are  called  Jelly-Fishes,  though  of 
these  also  there  are  a  number  differing  in  form 
and  size,  having  also  their  special  names. 
You  must  not  fancy  from  this  that  these  ani- 
mals are  in  any  way  connected  with  fishes. 
They  are  no  more  like  a  fish  than  a  bird  is  like 
a  fish,  but  this  common  name  has  been  given  to 
them  because  anything  that  lives  in  the  water  is 
apt  to  be  associated  with  fish  by  people  who 
know  nothing  about  them,  except  the  fact  that 
they  inhabit  the  sea. 

There  is  one  of  these  Hydroids  living  as  a 
single  animal,  not  in  a  community  or  cluster 
like  the  one  I  have  described,  which  is  exces- 
sively small,  perhaps  half  an  inch  high,  and  yet 
produces  some  of  the  largest  Jelly-Fishes.  It 
does  not  bear  them  by  buds  or  eggs,  as  I  shall 
show  you,  but  by  dividing  itself  into 
a  succession  of  animals,  each  one  of 
which  is  a  Jelly- Fish.  Here  is  a  pic- 
Hydroid  somewhat  magni- 


HYDROIDS   AND  JELLY-FISHES. 


51 


No.  27. 


fied,    and   before   this    process 
begins ;    and    here   in    another 
picture    of    the    same   after   it 
has  begun  to  divide,  and  very 
much    enlarged,    in    order    to 
show  you  how  this  change  takes  place.     After 
the  little  Hydroid    has  lived 
for  a  time  as  you  see  him 
in  the  first  picture,  a  single 
animal  attached  to  the  rocks 
or  sea-weed,  the  upper   part 
begins  to  contract,  then  an- 
other contraction  takes  place 
a  little   lower  down,  and  so 
on    till    the    whole     animal 
is    divided    by    contractions  No.  27  «. 

through  all  its  length,  and  it  looks  something 
like  a  pile  of  saucers.*  Then  each  one  of 
these  contractions  deepens 
more  and  more,  till  each  part 
that  has  been  so  marked 
off,  separates  from  the  rest, 
and  swims  away  a  free  an- 
imal, shaped  like  the  pic-  NO.  28. 

*  Strobila 


52  HYDROIDS  AND  JELLY-FISHES. 

ture  here.*  After  this  separation  has  taken 
place,  the  tentacles  begin  to  grow,  and  when 
the  animal  is  complete,  it  is  bordered  all 
around  the  margin  by  the  fringe  which  they 
form.  You  see  that  in  order  to  have  the 
bulging  side  above,  as  it  is  in  the  picture, 
each  one  as  it  floated  off  must  have  turned 
upside  down,  for  if  they  retained  the  position 
which  they  have  while  still  attached  together, 
their  shape  would  be  like  that  of  a  saucer, 
standing  on  its  bottom,  as  it  is  usually  placed. 
But  each  one,  as  it  leaves  the  pile  turns  a 
somerset,  and  though  it  has  still  the  shape  of 
a  saucer,  it  is  of  a  saucer  overturned  and  rest- 
ing on  its  edge,  the  edge  being  scalloped,  for 
the  fringe  of  tentacles  around  the  margin  is 
not  yet  fully  formed. 

There  are  a  variety  of  these  singular,  self- 
dividing  Hydroids  and  of  the  Jelly-Fishes  pro- 
duced by  them,  all  of  which  grow  to  a  con- 
siderable size.  The  most  common  is  the 
white  sun-fish,  f  so  called,  seen  in  our  bays 
and  along  our  wharves.  It  is  remarkable  on 

*  No.  28.    This  jelly-fish  has  been  described  as  Ephyra. 
f  No.  29.  Aurelia. 


HYDROIDS  AND  JELLY-FISHES.  53 

account  of  four  crescent-like  figures  of  a  rosy 
or  purplish  color,  so  placed  as  to  form  a  cross 


No.  29. 

in  the  centre.  These  are  produced  by  the 
large  accumulation  of  eggs  forming  these 
crescent-shaped  bunches.  Another  Jelly-Fish, 
produced  in  the  same  way  by  the  division  of 
a  Hydroid,  is  much  larger,  varying  in  circum- 
ference from  that  of  a  dinner  plate  to  that 
of  a  large  tub,  (I  have  often  seen  one  filling 
completely  the  largest  sized  wash-tub,)  and 
with  immensely  long  tentacles  hanging  from 
it.  When  one  of  the  largest  of  these  ani- 
mals is  swimming  in  the  sea,  its  tentacles 
may  stretch  out  for  twenty  or  thirty  feet  be- 
hind it.  The  color  of  this  Jelly-Fish  is  a  deep 
claret,  and  it  is  by  no  means  so  transparent 
and  delicate  as  the  others  I  have  described. 
Yet,  though  it  has  a  great  deal  more  solidity,  it 


54  HYDROIDS   AND  JELLY-FISHES. 

is  soft  nevertheless,  of  the  consistency  of  jelly, 
and  after  the  autumn  storms  it  is  seen  in 
large  numbers  strewn  upon  the  beach  like 
immense  cakes  of  brown  jelly.  So  large  a 
part  of  the  weight  of  Jelly-Fishes  is  derived 
from  the  water  they  absorb,  that  a  Jelly-Fish 
weighing,  when  taken  from  the  sea,  thirty- 
five  pounds,  if  left  to  dry  in  the  sun  will 
shrink  to  a  film  weighing  only  half  an  ounce. 
All  those  jelly-like  masses  which  s'ometimes 
lie  stranded  in  such  numbers  along  the  beach 
in  summer,  and  which  are  often  called  Sun- 
Fishes,  are  Jelly-Fishes  of  different  kinds. 

There  is  one  of  the  Hydroid  communities 
that  is  curious  and  interesting,  because  each 
individual  in  it  has  its  appointed  work  to  do. 
Some  are  the  sportsmen  and  the  feeders  of 
the  community.  It  is  their  business  to  catch 
the  prey,  and  they  are  furnished  with  the  lasso 
cells  which  I  described  to  you  in  the  Anemone. 
They  fling  out  their  long  whips,  and  entangle  in 
them  the  little  shrimps,  shell-fish,  or  any  other 
food  that  may  fall  in  their  way.  They  have 
also  to  eat  and  digest  for  the  whole  family,  and 
then  the  food,  reduced  to  a  pulp  by  the  pro- 


HYDROIDS   AND  JELLY-FISHES. 


55 


cess  of  digestion,  passes  through  the  whole 
community  by  means  of  the  stems,  which,  as 
I  have  told  you,  are 
hollow  tubes,  and 
communicate  with 
each  other.  Next, 
there  are  the  swim- 
mers, for  this  commu- 
nity is  not  attached, 
but  floats  freely  in  the 
water;  their  office  is 
to  move  the  whole  es- 
tablishment,  and 
one  may  see  such  a 
Hydroid  community 
moving  along  like  one 
individual,  though  all 
the  motion  is  perform- 
ed by  these  swim- 
ming members  alone. 
Finally  there  are  those 
whose  business  it  is  No  3Q 

to  produce  the  buds,  that  bear  the  little  Jelly- 
Fishes,  and  so  well  is  this  wonderful  commu- 
nity regulated  that  each  one  performs  his  own 


56  HYDROIDS  AND  JELLY-FISHES. 

work  faithfully  and  never  interferes  with  the 
affairs  of  his  neighbor.*  Of  these  singular 
communities  there  are  many  kinds,  one  of  the 
most  remarkable  of  which  is  the  beautiful 
animal,  commonly  known  in  the  Gulf  of  Mex- 
ico, as  the  Portuguese  Man-of-War.f  The 
various  individuals  composing  the  community 
hang  down  like  long  bright-colored  stream- 
ers, attached  to  a  bladder  filled  with  air,  of 
the  size  of  a  large  pear,  and  not  unlike  it 
in  shape,  with  a  crest  rising  above  it,  some- 
times pink  or  purple,  and  sometimes  blue 
which  catches  the  wind  like  a  sail,  and  carries 
it  along  like  a  little  boat  upon  the  surface 
of  the  sea.  From  the  lower  side  of  the  blad- 
der hang  all  kinds  of  threads  and  bags,  being 
as  many  distinct  animals  of  smaller  kinds, 
but  having  immensely  long  tentacles,  capa- 
ble of  an  extraordinary  extension,  sometimes 
measuring  many  yards  when  stretched  to 
their  full  length.  Nothing  can  exceed  the 
beauty  of  these  brilliant  little  communities 
as  they  are  seen  on  the  water,  with  purple 
crest  erect,  their  numberless  graceful  feelers 

*  Siphonophorse.  f  No.  30.    Physalia. 


HYDROIDS  AND  JELLY-FISHES. 


57 


and  threads  spread,  sweeping  proudly  over  the 
surface  of  the  sea,  like  a  miniature  ship  un- 
der full  sail.  It  is  for  this  reason,  I  suppose, 
that  the  sailors  have  called  it  the  Portuguese 
Man-of-War. 

This  most  beautiful  kind  of  Hydroid  be- 
longs to  tropical  seas,  and  is  never  found  on 
northern  coasts.  But  we  have  many  varieties 
of  very  pretty  Hydroids  on  our  rocks  and 
beaches  which  you  can  easily  collect  for  your 
Aquariums,  all  producing  their  own  kind  of 
Jelly-Fish,  and  this,  in  its  turn,  bringing  forth 
again  the  same  kind  of 
Hydroid  from  which  it 
came.  Besides  those  I 
have  described,  there  is 
one  in  which  some  of 
the  buds  have  somewhat 
the  shape  of  little  bells.* 
Here  is  a  branch  of  one, 
and  you  see  that  the 
buds  are  not  all  alike, 
but  that  one  is  longer 
than  the  others,  and  has 

*  Campanularia. 


No.  31. 


58 


HYDROIDS   AND  JELLY-FISHES. 


No.  32. 


no  tentacles,  and  within  you  see  a  number 
of  little  spheres.  Those  are  the  buds,  about 
to  drop  out  as  little  Jelly-Fishes,*  somewhat 
different  from  the  one  I  first 

described,  but   equally  delicate 

* 
and  beautiful.     It  has  not  the 

long  threads  hanging  from  it, 
but  tentacles  surround  its  whole 
lower  edge  like  a  fringe.  From  the  eggs  of  this 
Jelly-Fish  will  be  reproduced  again  the  little 
flower-like  Hydroid  with  its  bell-shaped  buds 
from  which  it  was  born. 

Then  we  have  another  Hydroid  forming  also 
a  little  shrub-like  community,  which  bears  its 

Jelly-Fish  buds  among 


the  tentacles  at  the 
crown  or  summit  of 
each  individual.  The 
Jelly-Fish  born  from  it 
has  a  strange  name ; 
it  is  called  the  hunch- 
back,! on  account  of 
No.  33.  its  singular,  one-sided 

shape.     It  is  larger  on  one  side  than  the  other, 

*  Tiaropsis.  t  No  34.   Hypocodon. 


HYDROIDS  AND  JELLY-FISHES.  59 

and    on    that    side    it    has    one   long   tentacle 
with  buds  growing  upon  it.      This 
again   produces    the    Hydroid   from 
which  it  was  born.     Here  you  have 
a  little  picture  of  it. 

There  are  still  other  Jelly-Fishes 
and  very  beautiful  ones,  having  no 
connection  with  any  Hydroid,  and  NoT  34. 
simply  reproducing  themselves  by  eggs.  They 
may  be  found  on  our  coasts,  throughout  the 
spring  and  summer ;  and  I  hope  you  will  have 
many  a  good  ramble  on  the  rocks  and  beaches 
of  Nahant  to  find  both  Hydroids  and  Jelly- 
Fishes. 

There  is  one  thing  I  must  not  forget  to 
tell  you  about  the  Jelly-Fishes  before  we  leave 
them.  They  are  the  lamps  of  the  sea.  Have 
you  ever  heard  of  the  phosphorescence  of  the 
ocean  ?  It  is  a  strange  light  on  the  surface  of 
the  water,  in  the  midst  of  which  occasionally 
larger  luminous  globes  seem  to  float,  and  fol- 
lowing in  the  wake  of  vessels  as  they  cut 
their  way  through  the  waves,  or  seen  at  night 
along  the  line  of  foam  that  breaks  upon  the 
shore.  There  are  a  variety  of  luminous  ani- 


60  HYDROIDS  AND  JELLY-FISHES. 

mals  in  the  sea,  and   a   part  of    this  singular 
illumination  of  the  ocean  is  due  to  all  of  them, 
but  the  Jelly- Fishes  are  the  brightest  and  most 
beautiful.     The  large  ones  float  slowly  like  fire- 
globes   among   the   lesser   lights,  while    others 
sparkle  like  stars,  or  spread  a  more  diffused  and 
paler  light  over  the  water.     This  luminous  prop- 
erty of  the  Jelly- Fishes  belongs  to  their  more 
active  and  sensitive  parts,  and  the  light  is  more 
perceptible  when  a  vessel  breaks  the  surface  of 
the  sea,  or  where  the  waves   break   upon  the 
shore,  because  the  disturbance  of  the  waters  in 
which  they  float  excites  them  into  unusual  bril- 
liancy.    It  is  easy  to  watch  the  action  of  this 
singular  quality  in  the  Jelly-Fishes  by  keeping 
them   in   glass  jars  in  a   dark   place.     If  you 
trouble  the  water  by  passing  your  hand  through 
it,  they  will  begin  to  shine,  and   sometimes,  if 
you  have  one  of  the  larger  ones,  you  may  see 
the  light  run  along  the  more  highly  organized 
parts  of  the  whole  body.     He  seems  to  tell  you 
thus,  in  fiery  characters,  the  story  of  his  own 
structure. 


HYDROIDS   AND  JELLY-FISHES.  61 

I  have  told  you  that  all  animals  like  the  Sea- 
Anemone, —  that  is,  with  the  stomach  hanging 
in  the  centre,  and  the  rest  of  the  body  divided 
by  partitions,  —  are  called  Polyps.  As  we  have 
come  to  the  end  of  our  talk  about  Jelly-Fishes, 
I  will  give  you  their  scientific  name  also.  All 
animals  constructed  like  Jelly-Fishes, — that  is, 
with  a  transparent,  jelly-like  body,  traversed  by 
tubes  like  little  channels  running  through  it, 
and  with  the  stomach  hollowed  out  of  the  sub- 
stance of  the  body,  —  are  called  Medusae  or  Ac- 
alephs.  Now  I  will  tell  you  something  about 
Star-Fishes  and  Sea- Urchins,  or,  as  I  think  you 
have  heard  them  called,  Sea-Eggs. 


STAK-FISHES  AND   SEA-URCHINS. 


CHAPTER  IV. 


STAR-FISHES  AND  SEA-URCHINS. 


WE  will  begin  with  an  old  friend  of  yours,  — 
the  five-armed   Star- Fish  that  you  have  often 
collected  on  the    beaches.      There  is   no  trou- 
ble   in    hunting 
for    these    Star- 
Fishes  ;  there  is 
scarcely  a   pud- 
dle     or     sea- 
weedy     rock 
along   any   part 
of   the    Nahant 
shore    where 
they  are  not  to 
No.  35.  be    found    in 

numbers,  and  if  you  ever  have  an  opportunity 


STAK-FISHES  AND   SEA-URCHINS.  63 

of  rowing  in  a  boat  around  Egg  Rock  at  low 
tide,  you  may  see  them  by  hundreds,  especially 
at  the  side  of  the  rock  farthest  from  Nahant, 
where  there  is  a  very  populous  Star-Fish  settle- 
ment. But,  though  you  are  so  familiar  with 
their  general  appearance,  I  doubt  whether  you 
know  much  of  their  habits  of  life,  or  of  the 
way  in  which  they  are  made.  You  know  that 
they  move  about,  but  you  do  not  know  what 
organs  they  have  to  serve  them  as  legs ;  you 
know,  if  you  have  ever  watched  them  when 
alive,  that  their  lower  side  is  covered  with  all 
sorts  of  appendages  seeming  to  be  in  active 
motion,  but  you  do  not  know  what  office  these 
appendages  have  to  perform ;  you  take  it  for 
granted  that  they  eat,  but  you  do  not  know 
where  their  mouth  is,  and  I  think  you  could  not 
tell  me  whether  they  have  any  eyes  or  not.  Let 
us  see  what  is  the  meaning  of  these  differ- 
ent parts,  and  when  you  have  them  in  your 
Aquarium  next  summer,  you  will  have  more 
interest  in  watching  them  and  in  learning 
something  of  their  habits  of  life. 

In  the  centre,  on  the  lower  side,  you  will  see  a 
small   aperture  which   is  the   mouth,  and   that 


64  STAR-FISHES  AND   SEA-URCHINS. 

aperture,  like  the  mouth  in  Sea-Anemones  or 
Jelly-Fishes,  opens  into  a  cavity  which  is  the 
stomach,  and  from  that  cavity,  tubes  run  up 
each  of  the  arms  to  its  extremity,  so  that  their 
food,  passing  from  the  stomach  into  these  tubes 
can  circulate  through  the  whole  body.  They 
have  a  very  singular  way  of  obtaining  their 
food.  They  have  no  long  tentacles  like  the  Sea- 
Anemone  to  catch  their  prey,  but  they  turn  the 
stomach  out  over  the  food,  enveloping  it  in  this 
way,  and  having  so  secured  it,  they  turn  it  back 
again.  On  the  lower  side  of  the  Star- Fish,  ar- 
ranged along  the  centre  of  each  ray  or  arm, 
there  are  a  number  of  small  appendages  that 
look  like  short  feelers ;  they  are  almost  con- 
stantly in  motion,  and  if  you  look  at  them 
closely  you  will  see  that  the  end  of  each  one 
spreads  very  slightly  into  a  club  shaped  extrem- 
ity and  has  a  small  depression,  forming  a  little 
pit.  These  are  their  organs  of  locomotion ;  they 
are  suckers,  and  are  so  constructed  as  to  cling 
closely  to  any  surface  they  touch.  When  the 
Star-Fish  wants  to  move,  he  stretches  one  of 
his  arms  in  the  direction  in  which  he  means 
to  go,  and  attaching  his  suckers  to  a  rock  or 


STAR-FISHES  AND  SEA-URCHINS.  65 

sea- weed,  or  any  object  near  him,  he  drags  him- 
self along.  You  know,  when  you  are  climb- 
ing a  tree,  and  you  come  to  a  part  of  it  where 
there  is  no  branch  upon  which  you  can  fix  your 
foot  to  take  the  next  step,  you  may  stretch  your 
arms  to  some  higher  bough,  and  draw  the  rest 
of  your  body  up  in  that  way.  This  is  not  un- 
like the  Star- Fish's  way  of  moving ;  he  turns  one 
of  his  rays  in  the  right  direction,  stretches  his 
suckers  as  far  as  he  can,  adheres  by  them 
closely  to  the  surface  along  which  he  is  mov- 
ing, and  drags  the  rest  of  his  body  on  by  the 
force  of  their  adhesion.  To  be  sure,  it  is  a  slow 
and  clumsy  way  of  moving,  but  then  the  Star- 
Fish  is  rather  a  dull  fellow,  and  he  is  as  well 
satisfied  if  he  has  walked  an  inch  or  two  in  an 
hour  as  you  would  be  if  you  had  walked  a  mile 
in  half  that  time.  These  suckers  are  placed 
along  the  centre  of  the  lower  side  of  each  ray, 
as  I  have  told  you,  and  on  each  side  of  the  row 
of  suckers  along  the  edge  of  every  ray  there  are 
appendages  of  a  different  kind.  These  are  stiff 
spines,  the  object  of  which  is  not  well  under- 
stood, but  perhaps  they  serve  as  a  protection  to 
the  animal.  Here  is  a  picture  of  a  single  ray, 


STAR-FISHES  AND   SEA-URCHINS. 

which  shows  you  the  suckers  and  the 
spines.  At  the  end  of  each  ray  there 
is  a  little  red  speck  which  is  an  eye, 
so  that,  as  they  have  five  rays,  they 
have  also  five  eyes,  which  I  dare  say 
will  give  you  a  great  respect  for  their 
powers  of  vision.  But  let  me  tell 
$  you  that  five  of  their  eyes  are  by  no 
/  means  so  good  as  one  of  yours,  and 
indeed  though  these  red  specks  are 
No.  36.  essentially  organs  of  sight,  it  is  very 
doubtful  how  much  they  see  with  them.  Per- 
haps they  are  only  receptive  of  light  without 
discerning  any  objects  ;  for  though  we  call  them 
eyes,  they  have  no  complicated  structure  such 
as  our  eyes  have  by  which  every  object  is  dis- 
tinctly drawn  like  a  picture  within  them.  Yet 
I  once  heard  a  story  of  a  Star- Fish  which 
inclined  me  to  believe  that,  if  they  do  not  see, 
they  have  at  least  some  very  keen  perception  of 
what  goes  on  about  them. 

Star- Fishes  carry  their  eggs  near  the  mouth, 
and  keep  them  safely  by  stretching  their  suckers 
around  them,  and  thus  holding  them  fast.  A 
friend  of  mine  was  one  day  watching  a  Star- Fish 


STAR-FISHES  AND   SEA-URCHINS.  67 

in  a  large  glass  dish,  which  had  its  eggs  folded 
within  the  suckers  in  this  way,  and  wishing  to 
examine  the  eggs  more  closely,  he  parted  the 
suckers,  took  the  eggs  away,  and  kept  them  for 
some  time.  When  he  had  finished  his  exam- 
ination, he  dropped  them  back  into  the  dish. 
At  once,  to  his  surprise,  the  Star- Fish  seemed 
to  be  aware  that  its  eggs  had  been  returned 
to  it,  and  moving  towards  them  at  its  utmost 
speed,  (which  is,  at  best,  but  creeping  very 
slowly,)  it  placed  itself  over  them,  folded  its 
suckers  once  more  around  them,  and  so  took  them 
up  again.  Wishing  to  be  quite  sure  that  this 
had  not  been  accidental,  he  removed  the  eggs 
again,  put  the  Star-Fish  into  another  and  larger 
dish,  and  having  placed  it  at  one  end,  and  put- 
ting also  some  obstacle  in  the  centre  of  the  dish 
to  divide  it  from  the  other  side,  he  then  dropped 
the  eggs  in  at  the  end  opposite  the  parent,  as  far 
from  it  as  possible.  The  Star- Fish  immediately 
began  its  journey  (now  quite  a  long  one  for  a 
Star-Fish)  toward  its  offspring,  and  having 
reached  them,  covered  them,  and  took  them  up 
again  as  before.  A  third  time,  the  experiment 
was  repeated,  but  always  with  the  same  result ; 


68  STAK-FISHES  AND   SEA-URCHINS. 

the  creature  perceived  its  eggs  the  moment  they 
were  placed  in  the  same  vessel  with  itself,  and 
went  at  once  to  shelter  and  protect  them.  You 
see  by  this  it  is  not  lost  time  to  watch  even 
these  lowest  creatures  that  God  has  made.  They, 
too,  care  for  and  cherish  their  young,  they  have 
certain  ends  to  fulfil  in  life,  and  they  enjoy  the 
existence  that  has  been  granted  to  them,  as 
well  as  the  higher  animals.  We  may  study  the 
habits  even  of  a  Star- Fish  with  interest,  when 
we  remember  that  these  first  stirrings  of  sense 
and  love  of  offspring  in  the  humblest  creatures 
rise  to  their  greatest  glory  as  affection  and  rea- 
son in  man,  and  place  him  at  the  head  of  all 
created  beings. 

Let  us  look  now  at  the  upper  side  of  the  Star- 
Fish.  It  is  studded  all  over  with  little  knobs, 
differing  in  color  in  different  Star-Fishes,  and 
having  the  effect  of  a  sort  of  inlaid  work, 
as  pretty  as  any  of  man's  devising,  or  even 
prettier.  (See  wood-cut  35.)  Between  these 
knobs,  are  very  short,  hollow  tubes,  so  small  that 
you  will  not  easily  distinguish  them,  but  it  is 
owing  to  them  that  the  upper  side  of  the  Star- 
Fish  has  its  full  and  rounded  outline.  These 


STAR-FISHES  AND  SEA-URCHINS.  69 

tubes  absorb  water,  and  when  a  Star- Fish  has 
been  left  upon  the  rocks  or  beach  by  the  retreat- 
ing tide,  its  outline  becomes  comparatively  flat, 
but  as  soon  as  the  tide  comes  up  and  covers  it 
again,  it  assumes  its  rounded  shape  once  more, 
by  filling  its  whole  body  with  the  water  which 
enters  through  these  minute  tubes.  If  you  watch 
them  when  they  have  just  been  taken  from  the 
sea,  you  may  see  the  water  oozing  from  these 
tubes. 

On  the  upper  side  of  the  Star- Fish,  near  the 
centre,  and  between  two  of  the  arms,  you  will  see 
that  there  is  always  a  round,  bright  colored  spot. 
That  is  a  little  sieve  through  which  the  water  is 
filtered  as  it  passes  into  the  five  principal  tubes 
that  run  from  the  stomach  to  the  extremity  of 
each  of  the  arms.  By  this  means  a  free  circu- 
lation is  established  through  the  whole  body. 

There  are  a  great  variety  of  Star- Fishes;  some 
in  which  the  arms  are  very  spreading,  being 
divided  into  branches  and  tendrils,  as  it  were, 
that  extend  in  every  direction,  but  yet  bear  the 
same  relation  to  the  centre  as  the  rays  in  the 
one  with  which  you  are  familiar;  others  in  which 
the  arms  are  united  for  a  part  of  their  length,  so 


70  STAR-FISHES  AND   SEA-URCHINS. 

that  the  compact  centre  is  larger ;  others  in  which 
there  are  ten  arms  instead  of  five,  and  so  on.  I 
will  not  tire  you  with  the  details  of  these  varie- 
ties, because,  however  their  appearance  may  dif- 
fer, the  structure  of  one  explains  the  structure  of 
all.  In  all  these  the  mouth  and  stomach  are 
in  the  centre,  the  tubes  extending  through  the 
arms,  the  suckers  and  spines  on  the  lower  side, 
the  knobs  and  tubes  on  the  upper  side,  and  the 
little  sieve  for  admitting  water  into  the  body. 
Those  in  which  the  arms  are  very  slender  and 
long,  or  branching,  however,  have  no  eyes  at  the 
tips. 

There  is  one  kind  of  Star-Fish  of  which  I 
wish  to  tell  you  something,  not  in  order  that 
you  may  study  it  for  yourselves,  for  it  is  not 
found  on  our  coasts  and  you  may  never  have 
an  opportunity  of  seeing  it,  but  because  it  re- 
sembles the  first  Star- Fishes  that  ever  were  cre- 
ated. It  is  found  in  the  West  Indies,  in  deep 
water,  and  instead  of  moving  freely  about  in 
the  water  like  the  others,  it  grows  upon  a 
stalk  attached  to  the  ground.  Sometimes  in 
breaking  up  or  blasting  rocks,  there  have  been 
found  upon  them  impressions  that  looked  as  if 


STAR-FISHES  AND   SEA-URCHINS. 


71 


some  large  but  graceful  flowers,  not  unlike  a 
widely  opened  tulip  or  lily,  only  of  great  size, 
had  been  roughly  drawn  there.  At  first,  the 


No.  37. 

persons  who  found  these  strange  old  flowers,  as 
they  seemed,  buried  in  the  rocks,  could  not  un- 
derstand how  they  came  to  be  there,  or  what 
they  were,  but  from  their  appearance  they  were 
called  "  stone  lilies."  But  when  they  were 


72  STAR-FISHES  AND   SEA-URCHINS. 

more  closely  examined,  and  carefully  studied 
by  naturalists,  who  were  familiar  with  animal 
structures,  it  was  found  that  what  looked  like 
a  flower-cup  was  a  kind  of  Star- Fish,  growing 
upon  a  tall  stalk,  which  must  have  been  at- 
tached to  the  ground  when  the  creature  was 
alive.  And  so  they  were  no  longer  considered 
as  flowers  of  old  times  that  had  been  hidden 
away  in  the  rocks,  and  they  lost  their  pretty 
name  of  "  stone  lilies,"  and  are  now  called 
Crinoids,  the  first  animals  of  this  kind  that  ever 
lived. 

You  will  wonder,  perhaps,  how  we  know 
that  they  were  the  first.  We  know  it  because 
they  are  found  in  very  ancient  rocks,  where 
are  preserved  the  impressions  of  a  variety 
of  animals  that  lived  many  thousand  years 
ago,  —  Corals,  Star-Fishes,  shells,  worms,  queer 
crabs,  and  strange  fishes,  old-fashioned  crea- 
tures, very  unlike  those  living  on  the  earth 
now,  that  vanished  away  many,  many  cen- 
turies ago,  and  only  left  their  traces  in  the 
rocks  to  tell  us  something  of  the  story  of  those 
strange  old  times,  before  man  and  the  animals 
living  with  him  upon  the  earth  were  born. 


STAE-FISHES  AND  SEA-URCHINS. 


73 


And  perhaps  you  may  ask  another  question, 
—  how  it  happens  that  any  animals  could  be 
preserved  in  hard  rocks  ?  At  the  time  these 
animals  were  buried  there,  these  rocks  were 
not  hard.  Many  kinds  of  rock  are  mud  or 
sand  at  first,  and  they  become  hard  in  the 
course  of  time,  by  the  continual  pressure  of 
the  layers  of  mud  and  other  materials  that 
are  constantly  added  year  by  year,  till  the 
whole  mass  is  consolidated  into  rock.  Now, 
during  this  process,  which  may  last  for  centu- 
ries, many  animals  die  in  the  soft  mud  or  sand 
that  is  afterwards  to  become  hard,  and  the  solid 
parts  of  their  bodies  are  preserved  there  and 
are  built,  as  it  were,  into  the  forming  rocks. 

Let  us  look  now  at  the  Sea-Urchin,  or  Sea- 
Egg.  Though  it  looks 
very  unlike  a  Star- 
Fish,  it  is  almost  ex- 
actly  like  it  in  the 
number  and  arrange- 
ment  of  its  parts. 
The  arms  which  are 
stretched  out  in  a  five- 
rayed  Star-Fish,  if 


74  STAR-FISHES  AND   SEA-URCHINS. 

drawn  together  and  joined  at  the  points,  would 
make  a  Sea- Urchin  ;  the  rows  of  suckers  and 
spines  arranged  along  the  five  rays  in  the  Star- 
Fish,  are  arranged  in  alternate  rows  up  and 
down  the  surface  of  the  Sea- Urchin,  the  five 
eye-specks  at  the  extremity  of  the  rays  in  the 
Star-Fish,  are  drawn  close  together  on  the 
summit  of  the  Sea-Urchin,  and  the  mouth  is 
placed  at  the  centre  of  the  lower  side  in  the 
Sea-Urchin,  as  in  the  Star- Fish ;  but  it  has  five 
little  teeth  not  to  be  found  in  the  Star- Fish. 
The  tubes  carried  along  the  arms  of  the  Star- 
Fish,  follow  the  line  of  the  rays  in  the  Sea- 
Urchin,  and  the  little  sieve  through  which  the 
water  enters  them  is  on  the  upper  side  of  the 
body,  between  two  of  the  rays.  You  may  form 
some  idea  of  the  way  in  which  the  difference 
in  the  outline  of  a  Star-Fish  and  a  Sea- 
Urchin  is  produced,  by  making  five  equal  divi- 
sions on  the  skin  of  an  orange,  leaving  them 
united  at  the  base, — then  peel  it  off,  and  stretch 
it  out,  you  have  a  star  with  five  rays,  —  draw 
the  rays  together,  and  unite  them  at  the  top? 
and  you  have  again  the  round  form  of  the 
orange. 


STAR-FISHES  AND   SEA-URCHINS.  75 

The  Sea-Urchin  has  one  very  peculiar  habit. 
He  bores  for  himself  a  hole  in  the  rocks,  which 
just  fits  him,  and  makes  a  very  snug  and 
comfortable  retreat.  I  have  seen  a  dead  Sea- 
Urchin  about  as  large  round  as  a  five  cent 
piece,  packed  away  as  closely  as  possible  in 
its  hole,  that  fitted  him  as  neatly  as  if  it 
had  been  cut  with  the  nicest  instrument. 
Their  mode  of  making  these  holes  is  not 
known,  and  as  they  are  found  in  all  kinds  of 
rocks,  whether  hard  or  soft,  where  Sea- Urchins 
exist,  in  granite  or  basalt,  as  well  as  in  lime- 
stone or  sandstone,  it  is  difficult  to  under- 
stand how  animals  not  furnished  with  any 
sharp  and  powerful  instrument  can  produce 
such  an  effect.  There  is,  however,  no  doubt 
that  these  holes  are  made  by  the  animals 
themselves,  not  only  because  the  Sea-Urchins 
are  found  in  them,  but  because  they  fit  their 
inhabitants  so  perfectly,  that  no  animal  not 
exactly  of  the  same  shape  and  size  could  have 
produced  them ;  and  they  are  of  all  sizes,  from 
that  of  the  young  Sea-Urchin  to  the  full  grown 
one.  It  has  been  supposed  by  some  natural- 
ists that  they  were  made  by  the  constant  fric- 


76  STAR-FISHES  AND   SEA-URCHINS. 

tion  of  a  fringe  that  is  in  unceasing  motion, 
called  the  vibrating  cilia,  which,  though  in- 
visible to  the  naked  eye,  covers  the  spines 
of  the  Sea- Urchin,  and  by  the  constant  turn- 
ing of  the  animal  over  and  over  in  the  same 
spot  may  wear  a  hole  in  the  rock.  It  seems 
difficult  to  believe  that  a  substance  so  soft 
and  delicate  as  the  vibrating  fringes  on  these 
animals  should  produce  any  effect  on  a  sub- 
stance hard  as  granite,  yet  we  know  that  the 
constant  dropping  of  water  wears  away  a 
stone,  and  it  may  be  that  the  continual  fric- 
tion even  of  the  soft  parts  of  the  Sea- Urchin 
would  be  equally  effectual. 

The  common  Sea-Urchin  of  Nahant  is  one 
of  those  that  make  these  singular  holes,  and 
you  may  have  an  opportunity  of  seeing  them 
in  the  rocks  there.  I  hope  you  will  try  to 
find  some  Sea- Urchins  for  your  Aquarium  next 
summer,  and  watch  them  in  their  living  con- 
dition. I  dare  say  you  have  often  seen  them 
dead  and  dry  on  the  beaches,  but  you  cannot 
then  judge  at  all  of  their  appearance  when 
living.  They  look  very  pretty  when  dried  in 
that  way,  because,  though  they  have  lost  all 


STAR-FISHES  AND   SEA-URCHINS.  77 

their  spines  and  suckers,  the  spots  where  these 
appendages  were  attached  form  a  sort  of  pat- 
tern in  regular  rows  or  zones  over  the  surface 
of  the  animal,  and  you  can  trace  in  this  pat- 
tern the  lines  along  which  the  spines  and 
suckers  were  arranged  when  the  animal  was 
living.  The  broader  rays  with  the  largest 
spots  are  those  along 
which  the  spines  were 
attached,  the  narrower 
ones  with  the  smaller 
spots  crowded  closely 
together,  are  those  along 
which  the  suckers  were 
placed.  No.  39. 

There  is  a  great  variety  among  the  Sea- 
Urchins  as  well  as  among  the  Star-Fishes. 
They  do  not  all  burrow  in  the  rocks.  Some 
of  them  are  flat  in  form,  and  live  on  sandy 
flats,  burying  themselves  in  the  sand,  so  that 
they  are  only  discovered  when  left  bare  after 
storms,  or  in  very  still  days,  when,  in  changing 
their  place,  they  have  left  tracks  along  the 
sand. 

There  is  another  animal   which,  though  it 


78 


STAR-FISHES  AND   SEA-URCHINS. 


No.  40. 


differs   strikingly  in  appearance  from  the  Sea- 
Urchin  and  the  Star-Fish  is  yet  constructed  on 

the  same  plan. 
It  is  commonly 
called,  from  its 
form,  the  Sea 
Cucumber.*  It 
may  be  a  little 

difficult  to  show  you  how  this  soft  elongated 
animal,  resembling  a  worm  more  than  anything 
else,  is  related  to  the  Star- Fish  with  its  extended 
rays,  or  the  Sea- Urchin  with  its  round  outline, 
but  I  will  try  to  explain  it  to  you.  Imagine  that 
the  Sea- Urchin  were  elastic,  and  that  taking 
him  at  the  mouth  on  one  side,  and  at  the  spot 
just  opposite  to  the  mouth  where  the  rays  meet 
on  the  other  side,  you  could  stretch  him  out 
till,  instead  of  being  a  round,  compressed  ball, 
he  would  have  a  long,  cylindrical  form  like  a 
large  worm ;  you  would  then  have  an  animal 
like  the  one  of  which  I  speak.  The  rays  would 
of  course  be  stretched  out  also,  and  would  ex- 
tend from  one  end  of  the  body  to  the  other. 
This  is  the  case  witK  the  Sea- Cucumber.  It  has 

#  Holothuria. 


STAR-FISHES  AND   SEA-URCHINS.  79 

no  spines,  being  soft  throughout,  but  the  suck- 
ers are  arranged  in  rows  along  the  body,  al- 
ternating with  spaces  having  no  appendages, 
but  corresponding  to  those  on  which  the  spines 
are  arranged  in  Star-Fishes  and  Sea- Urchins. 
The  mouth  is  at  one  end  of  the  body,  and  is 
surrounded  by  a  wreath  of  tentacles,  and  the 
animal  resting  on  one  side,  moves  along  like 
the  Star-Fish  and  the  Sea- Urchin,  by  means 
of  the  suckers,  always  turning  that  end  of 
the  body  at  which  the  mouth  is  placed  in 
the  direction  of  its  motion.  Its  body  is,  as  I 
have  said,  soft  throughout,  and  can  contract 
and  expand,  making  itself  broader  and  shorter, 
or  longer  and  narrower,  by  taking  in  or  let- 
ting out  the  sea-water,  which  enters  at  the 
opening  opposite  the  mouth,  at  the  other  end 
of  the  body.  The  main  tubes  for  the  circula- 
tion of  food  and  water  throughout  the  body, 
answering  to  those  which  in  the  Star- Fish  run 
along  the  arms,  and  in  the  Sea- Urchins  along 
the  rows  of  suckers,  in  the  Sea- Cucumber  ex- 
tend from  one  end  of  the  body  to  the  other,  and 
the  sieve  through  which  the  water  is  filtered  is 
within  the  body  instead  of  being  on  the  outside, 


80  STAR-FISHES  AND   SEA-URCHINS. 

as  in  the  two  others.  The  animals  of  this  kind 
that  are  found  on  our  coast  are  very  small. 
But  the  larger  kinds  abound  in  the  Bay  of 
Fundy  and  upon  the  mud-flats  of  the  Reef  of 
Florida.  Some  of  those  from  Florida  are  as 
large  as  your  arm  and  more  than  a  foot  long. 
This  curious  animal  furnishes  a  very  impor- 
tant article  of  food  to  the  Chinese.  They  call 
it  the  Trepang,  and  they  send  every  year  large 
fishing  fleets  to  the  islands  in  the  Pacific,  and 
to  the  coasts  of  New  Holland,  for  the  express 
purpose  of  collecting  it.  When  dried  and  pre- 
served in  a  particular  way,  they  find  it  a  great 
delicacy,  though  I  doubt  whether  you  or  I 
would  like  it  very  much. 


As  there  is  one  general  name,  that  of 
Polyps,  including  all  animals  of  the  kind  which 
I  first  described,  like  the  Sea- Anemone,  and 
another,  that  of  Medusae  or  Acalephs,  including 
all  of  the  second  kind,  like  the  Jelly-Fishes,  so 
*there  is  also  a  general  name  for  all  animals 
like  the  Star-Fishes,  Sea-Urchins,  and  Sea- 
Cucumbers, —  that  of  Echinoderms.  Each  of 


STAR-FISHES   AND   SEA-URCHINS.  81 

these,  the  Polyps,  the  Acalephs,  or  Medusae,  and 
the  Echinoderms  form  what  is  called  by  natural- 
ists a  class,  and  these  three  classes  are  included 
under  another  name,  that  of  Radiates.  In  other 
words,  Radiates  form  one  great  division  of  ani- 
mals, embracing  Polyps,  Acalephs,  or  Medusae, 
and  Echinoderms.  Now  if  you  look  in  your 
dictionary  for  the  definition  of  the  verb  "  to 
radiate  " — you  will  find  this  :  "  to  send  out  rays 
from  a  centre."  This  explains  the  structure 
of  all  the  animals  belonging  to  this  division, 
and  the  reason  why  they  are  called  by  this 
name.  Whether  they  are  round  or  long  or 
star-shaped,  they  are  all  so  constructed  that 
their  parts  diverge  from  a  centre,  and  at  that 
centre  is  an  opening  which  is  the  mouth. 

This  is  the  end  of  my  stories  about  Radiates, 
dear  Lisa  and  Connie,  and  I  hope  you  will 
forgive  this  little  bit  of  science  and  the  hard 
names  at  the  close.  If  the  account  of  them  has 
interested  you,  you  will  not  find  it  difficult  to 
keep  many  of  these  animals,  about  which  we 
have  been  talking,  alive  in  your  Aquarium 
next  summer,  and  to  learn  a  great  deal  of 
their  habits. 


82  STAR-FISHES  AND   SEA-URCHINS. 

If  you  like  this  little  lesson  in  Natural  His- 
tory, I  hope,  at  some  future  time,  to  write  an- 
other one  for  you  about  animals  of  another 
kind,  which  are  constructed  on  an  entirely  dif- 
ferent plan. 


THE  END. 


